Rock drill



E. B. MEAD Junel 18, 1940.

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Filed July 26, 1939 2 Sheets-Sheet 1 Ezra, Mea/gym June 1s, 1940.

E. B. IMEAD ao'cx DRILL Filed July 26, 1939 2 Sheets-Sheet 2 3ji 'EzraE. M e wm @am fm/Mj @www5 Patented June 18, 1940 UNITED STATES ROCKDRlLL Ezra B. Mead, Ottumwa, Iowa, assignor to Hardsoog Wonder DrillC'o., Ottumwa, Iowa, a

corporation of Iowa 'Application July 26, 1939, Serial N0. 286,675

6 Claims.

The present invention relates to rock drills of the type operated bycompressed air and it primarily has for its object to provide such adrill with improved valves so arranged and combined that, withoutchanging the position of the main control valve, the hole being drilledmay be blown by the simple operation of a push-button valve devicedirectly connected with the source of air supply to the drill, andwhereby the main valve may be used to direct the air for blowing thehole to the blow tube.

Again, it is an object to provide a drill of the character stated inwhich water may be delivered to the blow tube, while the air is alsopassing thereto, either while the drill is stopped or while it isrunning slowly, as may be desired.

Further, it is an object to provide a blowing device which is simple andeiective in operation, inexpensive to construct and maintain, and inwhich the use of valve springs may be omitted.

Other objects will in part be obvious and in part be pointed outhereinafter.

To the attainment of the above objects and ends the invention stillfurther resides in those novel features of construction, combination andarrangement of parts, all of which will be rst fully described in thefollowing detailed description and then be particularly pointed out inthe appended claims, reference being had to the accompanying drawings,in which:

Fig. 1 is a vertical section, on a small scale, on the line I-I of Fig.2, showing a rock drill embodying the invention.

Fig. 2 is an enlarged top plan view of the same, parts being brokenaway.

Fig. 3 is a section of the top or back head and the parts (other thanthe blow tube and ratchet bar) carried thereby.

Fig. 4 is a diagrammatic view of the parts of the back head with theinvention applied.

In the drawings, in which like numbers of reference indicate like partsin all the figures, I designates the cylinder, 2 the piston, 3 the eX-haust grooves, 4 the exhaust ports, 5 the pistons hammer part, 6 thegrooves in. the hammer part, 1 the friction ring which closes the upperend of the working chamber and 8 the cylinder collar which constitutesthe closure for the lower end of the working chamber.

The cylinder has live air inlet ports 9 (bottom end) and I3 (top end), afluid delivery duct I0 whose entrance ports II are at the shifting valvedevice I2; another set of ports I3 effects communication between theshifting valve and the upper end of .the working chamber.

g The shifting valve device may be of any usual kind, but I prefer touse the flap valve device of the kind shown in Fig. l and constitutingthe subject matter of another application, led July 19, 1939, Ser. No.285,449. '5

The cylinder I also has a live air duct I4 which conveys the live airfrom a duct 4I in the top or back head 2l] to the valve device I 2.

The front end I5 of the cylinder carries the rotatable sleeve Il whosefeathers or keys Ill register with the grooves 6. The sleeve Il has itslower end threaded internally and carries the chuck or holder I5 for thedrill steel I9 (see Fig. l).

The back head 20 has'the bored part 2| to receive the handle bolts 5S(of ordinary construction) It is also bored and tapped at 22 to providea chamber 55 and to receive a chambered plug 23, which not only closesthe chamber 55 at the top but also aids the hollow-tube carrier 54 insupporting the blow tube 53. The head 20 is also provided with a bore 24constituting a valve chamber.

A duct 25 leads from this chamber 24 to the chamber 55 directly.

The push-button valve comprises a body having upper and lower pistonportions 26, 28 respectively, separated by a neck 2l. The piston portion28 has anannular groove 32 which, when the valve is closed, communicateswith duct 35, later again referred to.

The closed position of this valve is determined by engagement of theflange 29 with the shoulder formed at the juncture of the smaller withthe larger parts of the chamber 24.

The push-button valve may have an extension with a pocket to receive aspring 3| which may be used, if desired, .to move the valve to theclosed position or to assist in such movement. However, by properlyproportioning the valve structure, spring 3l becomes unnecessary, as theair admitted into the enlarged end of the chamber 24, through port 34,will suiiice to move the valve to closed position.

A button or head 33 is secured to the valve and provides a shoulder toengage the back head2!! on the down or in-stroke of the valve and limitit to a fully open position for eiecting communication between ducts 35and 25.

The back head also has an air space 35 into which, at 44, is screwed thegland-nut which carries the air inlet pipe 4B. The space 35 is inconstant communication with the source of compressed air supply via pipe46 and also constantly communicates with duct 35.

A main valve 38 ts into a valve seat bore 3l and has its free end inchamber 36. It has a stem 51 which is fitted with a handle 58 (Figs. 4and 2). It also has a pocket or chamber 49 that constantly communicateswith the air space 36. Ports 39 are provided for conducting the motivefluid from chamber 36 to duct I4 via 4I, while a port 42 is designed, inone position of the valve, for registering with the duct 43. The mainvalve 38 also has a small port 55 for leading air to port 4I for slowrunning of the drill.

The back head 20 may, at a suitable place, have a duct 41 for deliveringwater to chamber 55 with which duct a water hose 48 and shut-ofi valve49 are connected.

59 designates a ratchet ring and 52 indicates the ratchet bar which isrifled to lit the rifle-nut 5l for the usual purposes.

The blow tube 53 is secured in the carrier 54 and which is held in placeby plug 23.

The parts I, l5 of the drill case and the head 2U may be bolted togetherby bolts 99, as. shown in Fig. 2.

From the drawings it will be seen that the blow tube 53 extends throughthe center of the ratchet bar 52 and through piston 2--5. It may or maynot be extended into the hole 6l of the drill steel as desired. In a drydrill it need not extend into the drill steel, but in a drill usingwater to allay the dust it should extend into the steel as shown in Fig.1.

Operation Assume the parts to be positioned as in Figs. l and 4. Airwill pass from chamber 36 through main valve 38, ports 39, 63, ductsll-I4 to distributing valve l2 for eliecting a normal operation of thepiston 2, etc., at such speed as desired accordingly as ports 39 areopen, more or less. Air under pressure will also occupy duct 55 and port34 and the lower end of chamber 24, thus holding push-button valveclosed.

To blow the hole, the Valve 33, 29, 21,29, 29 is pushed in until pist-on28 clears duct 3b, which allows full pressure air to ow via duct 25 tochamber 55, and from thence through 53 and the drill steel to the hole.The push-button valve 1s operable regardless of the position of valve38.

An independent method of blowing is also provided for. The duct 4| hasits ends G3 separated, leaving a blind center portion 52. In alignmentwith this portion 92 the port 42 of the valve 33 is located. The ports39, 42 and 5S are so arranged that when lever 58 is in one position allports will be closed; when the lever is in a second position ports39--39 will be open and ports 56 and 42 will be closed; when in a thirdposition ports 56 and 42 are open.

When the operator has reached the limit of one length of steel I9, hemoves handle lever 58 to the position where port 42 registers with duct43 to blow the hole, and then moves lever 58 to a position where allports of the valve 39 are closed.

When water is used to lay the dust, it is admitted by the hose 48 andregulating valve 49, not a part of the drill proper. rIhe regulatingvalve 49 is of such type as to permit the water to seep continually intospace 55, from which it is blown through the blow tube. Water used inthis connection is invariably at a lesser pressure than the air. In caseof excessive opening of its needle valve 49 water might flood the ducts25, 43, but due to the higher air pressure it could not go beyond thevalves 26 etc., and 38. The idea is so to adjust the pressure and amountof water fed as to prevent this flooding.

Since the drilling engine is of conventional construction, save as aboveindicated, further description of its operation is thought to beunnecessary.

From the foregoing description, taken in connection with theaccompanying drawings, it is thought that the complete construction,operation and advantages of the invention will be clear to those skilledin the art to which it relates.

What I claim is:

l. In a rock drill, having a back head unit and a blow tube carriedthereby, and having a working chamber, a main throttle valve carried insaid head, said head having an air receiving chamber in communicationwith said throttle valve, means to deliver compressed air into said airreceiving chamber, a duct between said air receiving chamber and theentrance of said blow tube, a pushbutton valve for controlling passagethrough said duct, said duct being independent of said throttle valve,another duct leading from said throttle valve to the entrant end of saidblow tube independent of said push-button valve, and a third ductleading from said throttle valve toward the working chamber of thedrill, said throttle valve having ports for communication with saidsecond and third ducts separately.

2. In a rock drill, having a back head unit and a blow tube carriedthereby, and having a working chamber, a main throttle valve carried insaid head, said head having an air receiving chamber in communicationwith said throttle valve, means to deliver compressed air into said airreceiving chamber, a duct between said air receiving chamber and theentrance of said blow tube, a push-button valve for controlling passagethrough said duct, said duct being independent of said throttle valve,another duct leading from said throttle valve to the entrant end of saidblow tube independent of said push-button valve, and a third ductleading from said throttle valve toward the working chamber of thedrill, said throttle valve having ports for communication with saidsecond and third ducts separately, and having a small port forcommunication with said third duct when the valve is also incommunication with said second duct.

3. In a rock drill, having a back head unit and a blow tube carriedthereby, and having a working chamber, a main throttle valve carried insaid head, said head having an air receiving chamber in communicationwith said throttle valve, means to deliver compressed air into said airreceiving chamber, a duct between said air receiving chamber and theentrance of said blow tube, a push-button valve for controlling passagethrough said duct, said duct being independent of said throttle Valve,another duct leading from said throttle valve to the entrant end of saidblow tube independent of said push-button valve, and a third ductleading from said throttle valve toward the working chamber of thedrill, said third duct having two entrance ports and said throttle valvehaving two separated ports for communicating with said two entranceports, and having a third port located in a plane between said twoseparated ports for communication with said second duct.

4. In a rock drill, having a back head unit and a blow tube carriedthereby, and having a work ing chamber, a main throttle valve carried insaid head, said head having an air receiving chamber in communicationwith said throttle valve, means to deliver compressed air into said airreceiving chamber, a duct'between said air receiving cham- 15 ber andthe entrance of said blow tube, a pushbutton valve for controllingpassage through said duct, said duct being independent of said throttlevalve, another duct leading from Said throttle valve to the entrant endof said blow tube independent of said push-button valve, and a thirdduct leading from said throttle valve toward the Working chamber of thedrill, said third duct having two entrance ports and said throttle valvehaving two separated ports for communicating with said two entranceports, and having a third port located in a plane between said twoseparated ports for communication with said second duct, said throttlevalve also having a minimum feed port for communication with said thirdduct when said two separated ports are out of communication with saidtwo entrance ports and said third port is in communication with saidsecond duct.

5. In a rock drill, having a back head unit and a blow tube carriedthereby, and having a working chamber, a main throttle valve carried insaid head, said head having an air receiving chamber in communicationwith said throttle valve, means to deliver compressed air into said airreceiving chamber, a duct between said air receiving chamber and theentrance of said blow tube, a push-button valve for controlling passagethrough said duct, said duct being independent of said throttle valve,another duct leading from said throttle valve to the entrant end of saidblow tube independent of said push-button valve, a third duct leadingfrom said throttle valve toward the working chamber of the drill, saidthrottle valve having ports for communication with said second and thirdducts separately, said first duct having offset ports communicating withthe valve chamber of said push-button valve at two levels, saidpush-button valve including a valve proper composed of two pistons and aconnecting neck and having a flange at one end, serving as a stop inclosed-valve position, and having means at the other end serving as astop in opened-valve position, and means to deliver air under pressurefrom said air-receiving chamber to the under side of said push-buttonvalve for closing the same.

6. In a rock drill, having a back head unit and a blow tube carriedthereby, and having a working chamber, a main throttle valve carried insaid head, said head having an air receiving chamber in communicationwith said throttle valve, means to deliver compressed air into said airreceiving chamber, a duct between said air receiving chamber and theentrance of said blow tube, a push-button valve for controlling passagethrough said duct, said duct being independent of said throttle valve,another duct leading from said throttle valve to the entrant end of saidblow tube independent of said push-button valve, a third duct leadingfrom said throttle valve toward the working chamber of the drill, saidthrottle valve having ports for communication with said second and thirdducts separately, said i'lrst duct having offset ports communicatingwith the valve chamber of said push-button valve at two levels, saidpush-button valve including a valve proper composed of two pistons and aconnecting neck and having a flange at one end, serving as a stop inclosed-valve position, and having means at the other end serving as astop in opened-valve position, means to deliver air under pressure fromsaid air-receiving chamber to the under side of said push-button valvefor closing the same, and spring means for assisting the closingmovement of said push-button valve.

EZRA B. MEAD.

